Various towable ground leveling devices exist in the prior art, such as U.S. Pat. Nos. 3,795,069 and 3,106,969. Also, there are several towable sled type devices for use with personal motorcraft, including a snowmobile and the like, namely, U.S. Pat. Nos. 5,119,752 and 3,741,577. Finally, the prior art also includes various towable devices specifically directed to snow grooming/leveling, such as those seen in U.S. Pat. Nos. 4,244,662, 3,915,239 and 3,478,827, and 3,872,931, 3,666,020 and 3,576,214. Of these, only the later three are nonindustrial type devices intended and able to be towed behind a snowmobile under operating conditions, i.e., at all speeds while traveling over a snowmobile trail.
Several disadvantages exist in these devices based on the devices themselves as well as the basic operating characteristics of a snowmobile. As is appreciated by one in this art and moreover the average snowmobile operator, most snowmobiles are driven by a centrally located track which comes into contact with the ground surface, usually snow, over which the snowmobile travels. During operation of the snowmobile, and particularly upon commencing forward travel, the snow engaging portion of the track, moving from a front of the snowmobile to the back, lifts up some of the snow it contacts and then propels or sprays it backwards at a track back location where the track loses contact with the snow covered surface.
As a result of the snow spray effect when the snowmobile commences operation, a pile of snow is usually deposited just behind the position where the back end of snowmobile was located. If the pile is left alone it merely represents a mound of snow in the snow trail. If this pile is traveled over by other snowmobiles it is compacted and eventually forms a mogul or the like. In either case, this one pile of snow creates an unlevel disturbance in the snowmobile trail. Such an unlevel disturbance is sometimes desirable to provide a more challenging snowmobile ride. However, even just one of these disturbances make operating a snowmobile somewhat hazardous given the uneven snow surface. Then, taking a popular snowmobile trail it is evident that over a period of time and with many snowmobiles traveling over the same trail, the snow mound/mogul effect would be multiplied and the destruction to the snowmobile quite significant.
To a somewhat lesser degree, but still significant and more so depending on the snow moisture conditions, during operation of the snowmobile the snow spray is continuously propelled outward and upward from the back of the snowmobile, but not at a constant rate. The amount of snow sprayed depends on the speed of the snowmobile and the snow moisture conditions. Thus, in the ordinary course of operating a snowmobile, simply changing speeds will, regardless of moisture conditions, vary the amount of snow sprayed whereby any positive differential amount will cause a snow mound, and in due course over time a mogul or the like.
One way to deal with the snow mound, moguls and the like is to remove them well after they have formed, i.e. with equipment that is proposed by the prior art devices. Such an approach is commendable, however, it ignores the bigger part of the problem, namely, its creation.
With the prior art devices, although removing the snow mound, moguls and the like solves one problem it often creates another bigger problem. Over a short period of time, employing one of the three non-industrial type devices tends to form a snow trail rut where the existing device scrapes over the snow trail and pushes the loose snow off or out of the sides of the device. As is obvious in geographical locations where there is not a steady supply of new snow or a substantial snow base, such a scraping action displacing the snow trail snow would destroy a snowmobile trail, making it unusable.
These and other types of trail smoothing or grooming devices disclosed in the prior art do not offer the flexibility and inventive features of my Snow-Handling Trail-Grooming Device. As will be described in greater detail hereinafter, the features, combination of features and improvements of the present invention differ from those previously proposed.